1. Field of the Invention
This invention relates generally to hydrometer devices for use within lead-acid storage batteries of the type installed within vehicles and the like. More particularly, the present invention relates to a battery hydrometer collar having a novel sealing means so as to provide a better seal upon insertion of the hydrometer into a pre-formed bore located within the top of a battery casing.
2. Description of the Prior Art
A prior art search directed to the subject matter of this application in the U.S. Patent and Trademark Office revealed the following U.S. Letters Patent:
______________________________________ 1,262,478 729,835 3,338,447 1,410,929 2,669,370 3,405,830 2,093,669 2,704,100 3,898,046 2,117,170 2,746,632 4,230,231 3,223,269 2,927,709 4,253,581 3,754,445 2,993,612 4,883,641 4,052,534 3,057,502 ______________________________________
In accordance with a known hydrometer device of the prior art for use within lead-acid storage batteries to be installed within automobiles, the hydrometer device includes a cylindrically-shaped collar member, a light transmissive rod, and a cage having a float ball. The upper end of the rod is connected to the cylindrically-shaped member, and the lower end of the rod is connected to the cage. The cylindrically-shaped collar member is provided with external ribs for frictional engagement with a corresponding opening defined within the battery casing wall so as to define a sealing relationship therebetween. Such prior art hydrometer device is shown in U.S. Pat. No. 4,240,282 to John F. Nelson, which is assigned to the same assignee of the present invention.
The principal unsolved problem of this prior art hydrometer device is that it does not always provide a satisfactory seal and thus oftentimes leaks. In other words, a sufficient seal between the collar member and the interior wall of the bore of the battery casing so as to prevent leakage of the acid from within the storage battery cannot be maintained at all times. Generally, this is because of wide tolerances encountered in the internal diameters of the battery casing bore along its axial length when the battery casings are commercially produced in large quantities and into which the collar members have to be fitted. Furthermore, in the manufacture of the battery casing bores there are produced at times various imperfections such as, for example, scratches, voids and the like upon the interior surfaces thereof.
Another difficulty with this prior art hydrometer device arises during its insertion into the battery casing bore by means of automatic assembling machines. Such machines automatically insert or drop the hydrometer device into the battery casing bore as the batteries are moved by means of conveyor and thereafter a downward force is applied to the top of the collar member so as to secure the hydrometer device within the battery casing bore. If the hydrometer device is not properly aligned within the battery bore, then some of the external ribs upon the collar member will possibly be damaged or destroyed thereby preventing a fluid-tight seal. In the event of imperfect operation of diameters, this will inevitably result in a tendency for the acid to be leaked from the battery.
In U.S. Pat. No. 3,223,269 to Harold W. Williams issued on Dec. 14, 1965, there is disclosed a screw cap closure for bottles which includes an outer wall and a hollow cylindrical, plug-type sealing member. In order to protect against leakage, the sealing member is formed with a circular bead which will be yieldingly pressed into engagement with and conforms to any irregularities of the shape of the inner surface of the bottle.
In U.S. Pat. No. 4,052,534 to John L. Devitt issued on Oct. 4, 19877, there is disclosed a battery vent plug for insertion into a battery case vent well which includes an 0-ring gasket positioned around the outer cylindrical surface of a lower cylindrical member for engaging the interior walls of the battery case vent well. The 0-ring gasket provides a gas-type seal with respect to the vent well when the plug is disposed therein.
In accordance with U.S. Pat. No. 2,669,370 to Ivey G. Royall, Jr. issued on Feb. 16, 1954, there is taught a rubber stopper which includes a cylindrical outer wall portion and an inner end closed off by means of a wall. The outer peripheral surface of the wall portion is provided with two sets of first and second ribs. The first set of ribs are arranged at the top of the wall portion and are made continuous throughout the periphery of the wall portion. The second set of ribs are arranged at the lower end of the wall portion and are made discontinuous by means of passageways so as to permit air to escape from the bottle during the initial movement of the stopper its operative sealing position. Thereafter, the first ribs are moved into engagement with the inner neck portion of the bottle for effecting a complete seal.
U.S. Pat. No. 2,746,632 to Carl Bramming issued on May 22, 1956, discloses a flexible cup-shaped closure member for a vacuum bottle which has an annular side wall. The outer surfaces of the side wall is provided with a plurality of ribs which prevent any liquid within the vacuum bottle from escaping therefrom.
U.S. Pat. No. 2,927,709 to H. O. Hoffman et al. issued on Mar. 8, 1960, shows a bottle stopple which includes a main body section having two axially spaced portions located at its axially inner end and extending across a slot. The spaced portions are compressible in a radial direction for facilitating engagement thereof with the opening of the bottle. A rib is formed upon the axially inner end of the body section for temporarily holding the stopple in engagement with the bottle.
U.S. Pat. No. 2,993,612 to Erich Trautuetter issued on July 25, 1961, discloses a bottle stopper comprised of a sealing neck and a stopper jacket. The sealing neck has upon its outside face a plurality of sealing lips which provides a sealing function with respect to the inner pressure of the bottle. The sealing lips are arranged in a spaced-apart and parallel relationship with respect to each other and are formed as closed annular ribs.
Furthermore, there are disclosed a number of other patents in the prior art which also show various types of stoppers having ribs or ridges so as to provide fluidtight sealing of a container as evidenced by means of U.S. Pat. Nos. 3,057,502 to Wood; 3,338,447 to Meyers, Jr.; 3,405,830 to Hayashida; and 3,898,046 to Ikeda et al. The remaining patents uncovered from the search but not specifically discussed are merely cited to generally show the state of the art and are directed toward various types of hydrometer devices and stoppers for sealing containers.
The present invention represents a substantial improvement over the aforementioned U.S. Pat. No. 4,240,252 which is hereby incorporated by reference. The hydrometer collar of the present invention includes a cylindrically-shaped member having an annular side wall, a plurality of sealing rings being formed upon the outer surface of the annular side wall, and a small wiping rib being formed integrally with each one of the plurality of sealing rings and extending radially outwardly therefrom. The wiping ribs are easily deformable so as to fill any imperfections existing upon the interior surface of the battery casing bore into which the collar is inserted, thereby creating a fluid-tight seal.